Traditional reduced complexity sequence estimation or trellis algorithms are based on best path search. Survivor paths are selected based on extended path metric calculation for every path candidate. The total number of extended path metrics is the product of the number of survivors and the symbol constellation size (Alphabet consists of M symbols), meaning that every survivor is duplicated M times in order to find the most probable successors (e.g., M-algorithm). Such process exhibits huge amount of complexity in case of large Alphabet size. In the presence of low SNR (close to the cutoff rate), it is required to increase the number of survivors beyond M to assure near ML (Maximum Likelihood) performance.